The present invention relates to firearms. More specifically, the present invention relates to electronically fired revolvers in which a latch mechanism is incorporated to release the hammer at a desired point in trigger motion after the cylinder has carried up.
Revolvers have been produced for over a century and, although continuous efforts have led to improvements in safety, manufacturing, and operation of revolvers, many components in their firing mechanism have remained relatively unchanged in function and design. Notably, the mechanical linkage between trigger, hammer and cylinder, i.e., the firing mechanism, still utilizes a basic design that requires direct engagement between the trigger and hammer in order to cock and fire the revolver.
In a conventional revolver a relatively large amount of force must be exerted on the trigger and main spring in order to load the hammer with enough potential energy to reliably discharge the cartridge. The relatively large force causes inherent problems in accurately aiming the firearm. This is especially problematic in double action (DA) revolvers, where the cylinder must be fully rotated, and the hammer must be cocked and fired in a single motion of the trigger.
Additionally, in double action revolvers, it is often difficult for an operator to discern the letoff point in the trigger movement, i.e., the point at which the movement of the trigger fully cocks the hammer and further trigger movement will release the hammer for firing. Moreover, the letoff point in a conventional firing mechanism varies greatly with tolerances and wear of the various mating surfaces involved in the linkage of the firing mechanism.
More recently, electronics have been incorporated into firearms to further improve the cost, manufacturability, and performance of the firearms. One such example of an electronic revolver is disclosed in the above referenced U.S. patent application Ser. No. 09/616,722 (xe2x80x2722).
Referring to FIGS. 1 and 2, an embodiment of a revolver in accordance with the xe2x80x2722 application is shown generally at 10. The xe2x80x2722 application describes a revolver 10 having an electronic firing apparatus adapted to produce a firing signal. The revolver 10 includes a frame 12, a cylinder 14 having a firing chamber to receive a cartridge therein. The revolver also includes a barrel with a firing axis attached to the frame in alignment with the firing chamber and a trigger 16. A linearly displaceable firing probe 18 (as opposed to a conventional firing pin) is disposed within the frame 12 for linear reciprocal movement from a probe recovered position, wherein the firing probe 18 is retracted away from the cartridge, to a probe contacting position, wherein the firing probe 18 is disposed forwardly in contact with the cartridge (not shown). Actuation of the trigger 16 causes the firing probe 18 to move from the probe recovered position to the probe contacting position only when an electronic security apparatus (not shown) determines the revolver 10 is in a firing mode and the operator is an authorized operator.
An embodiment of a firing mechanism in accordance with the xe2x80x2722 application is shown generally at 20. The firing mechanism 20 includes the trigger 16, a hammer 22, a sear 24, a transfer bar 25, a hand 26, a rebound 28, a main spring (or rebound spring) 30, a stirrup 32, and a link 34. A trigger lever 36 is coupled between the trigger 16 and the rebound 28 to compress the main spring 30.
The hand (or ratchet arm) 26 is connected to the trigger 16 via hand pin 27, and has a configuration and function known well in the industry to index the cylinder 14 as the trigger 16 is pulled. During actuation of the firing mechanism 20, it is important that the hand 26 fully index and align the cylinder 14 with the firing axis of the revolver 10 just before the trigger 16 reaches the letoff point and releases the hammer 22 for firing. For purposes of this application this indexing and alignment is defined as the xe2x80x9ccarry-upxe2x80x9d of the cylinder. In this regards, the tolerences of the hand pin 27 and the length of the hand 26 are critical for achieving carry-up.
Movement of the entire firing mechanism 20 is governed predominantly by three pivot pins which mount and secure the firing mechanism 20 in a cavity 31 of the frame 12. The stirrup 32 is pivotally mounted by a stirrup pin 38, the hammer 22 is pivotally mounted by a hammer pin 42, and the trigger is pivotally mounted by a trigger pin 40. The frame 12 has a contoured cam surface 44 located and shaped within the cavity 31 to guide the transfer bar 25 during early stages of firing mechanism 20 actuation described below.
The trigger 16 includes a trigger post 46 with a flat upper surface 48 which bears generally vertically against the distal end of the sear 24 during early stages of firing mechanism 20 actuation. The trigger post 46 defines a trigger pocket 50 that receives the transfer bar 25 throughout the entire cycle of firing mechanism 20 actuation. The lower end of the trigger pocket 50 forms a relatively sharp let-off apex 52 designed to engage a foot 54 of the hammer 22 during the later stages of firing mechanism 20 actuation.
FIG. 1 shows the firing mechanism 20 in its xe2x80x9crecovered positionxe2x80x9d, i.e., the normal rest position that the components of the firing mechanism 20 return (or recover) to when the revolver 10 is fired and the trigger 16 is released. FIG. 2 shows the relative position of the various components of the firing mechanism 20 at its let-off point, i.e., the point at which the hammer 22 is fully cocked. and further trigger 16 movement will release the hammer 22 from the trigger 16 for firing.
Problematically, as illustrated in FIG. 2, minor deviations in the trigger to hammer linkage will greatly affect the letoff point. That is, small tolerance or wear variations in the surfaces at the trigger""s letoff apex 52 and the hammer""s foot 54 can result in large angular deviations 56 in trigger position at the letoff point. Moreover, the tolerances and wear of the trigger pin 40 and hammer pin 42 also significantly contribute to the angular deviation 56.
Just as critically, the tolerances of the angular deviation 56 also affect the carry-up of the cylinder, i.e., indexing and alignment of the cylinder chamber with the firing axis, which must be accomplished just before the letoff point. This is because the hammer and hand are both directly engaged with the trigger. As a result, the carry-up is affected by both the trigger to hammer linkage as well as the trigger to hand linkage. That is, in addition to the angular deviation 56 caused from tolerances of the trigger to hammer linkage, the tolerances of the length of the hand 26 as well as the tolerances in the hand pin 27, i.e., the trigger to hand linkage, further exacerbate the problem of accurately achieving carryup. Moreover, because the hammer 22 and hand 26 are each directly linked to the trigger, 16, there is no way to separate the constraints of the trigger to hammer linkage from the trigger to hand linkage, therefore making manufacturing more difficult.
Based on the foregoing, it is the general object of the present invention to provide an electronically fired revolver that overcomes the problems and drawbacks associated with prior art revolvers.
The present invention offers advantages and alternatives over the prior art by providing a revolver having a latch mechanism between the hammer and trigger, such that the hammer does not directly engaged with the trigger during actuation of the firing mechanism. Accordingly, the linkage between the hammer and latch is separate from the linkage between the trigger and hand. As a result, the tolerance build up in each linkage can be treated as two parallel designs rather than being stacked in series upon one another, therefore simplifying production manufacture of the firing mechanism.
These and other advantages are accomplished in an exemplary embodiment of the invention by providing a revolver configured to discharge electrically fired cartridges. The revolver includes a frame, and a barrel with a firing axis attached to the frame, a cylinder and a firing mechanism. The cylinder is pivotally attached within an opening of the frame and has a plurality of firing chambers sized to receive the electrically fired cartridges. Each firing chamber is indexable to a carry-up position wherein the chamber is in alignment with the firing axis. The firing mechanism includes a trigger, a hand, a hammer and a latch mechanism. The trigger is pivotally attached to the frame to actuate the firing mechanism from a recovered position to a fired position. The hand is pivotally attached to the trigger such that the hand engages the cylinder to index the chambers to their carry-up positions during actuation of the firing mechanism. The hammer is pivotally attached to the frame. The latch mechanism is pivotally attached to the frame wherein the latch mechanism engages the hammer in a set position during actuation of the firing mechanism. When the chambers reach their carry-up positions, the latch releases the hammer from the set position to displace the firing mechanism to the fired position to fire the revolver.
In an alternative embodiment of the invention, the revolver includes the hammer having a forwardly extending hook portion and the latch mechanism having a rearwardly extending ramp. In the set position, the hook of the hammer engages the ramp of the latch mechanism to prevent the hammer from rotating.
In another alternative embodiment of the invention the revolver includes the hammer having a hammer foot at its lower distal end. A rebound is slidably mounted to the frame and the rebound has a hammer stop protruding upwardly therefrom. When the firing mechanism returns to the recovered position the rebound slides under the hammer such that the hammer stop rotates the hammer foot to disengage the latch mechanism from the hammer.